Expanding rotary reamer



'Mwah 4 F. STONE EXPANDING R OTARY BEAMER Filed April 1l, 1922 5Sheets-Sheet 1 l mvENToR A 25 Freder/c/r 370 ne.

ATTORNEY March 4 E924.

` F. STONE EXPANDING ROTARY REAMER Filed April 1l, 1922 3 Sheets-Sheet 2ATTORNEY March 4 F. STONE EXPANDING ROTARY REAMER Filed April 11. 1922 3shetssheet :a

2 5 k IVN Patented Man, 1924.

iaeaaaa NETE@ TAFS PATENT @FFHCCQ FREDMICK STONE, 0F SPOKANE,WASHINGTON, ASSIGNOR T0 DIMOND DRILL CON- TRCTING COIVIPANY, 0F SPOKNE,WASHINGTON'.

EXPANDIN G ROTARY BEAMER.

Application led April 11, 1922. Serial No. 551,549.

To all whom it may concern.'

Be it known that I, FREDERICK STONE, a citizen of the United States,residing at Spokane, Spokane County,- and State of Washington, haveinvented certain new and useful Improvements in Expanding RotaryReamers, of which the following is a specication.

My present invention relates to improvements in expanding 'rotaryreamers especially adaptedfor use in connection with a lead drill orbit, in the operation of drilling for water, oil, or gas and the like,either to remove a solid core orv pulverized dbris from material asminerals or rock. Simultaneously with the drilling operation of thecenter drill or bit at the lower end Vof the drilling tool, thepreviously drilled center hole is enlarged by the utilization of thelaterally proJecting underreaming cutters. This enlarged hole isrequired for the accommodation of the couplings and of the well casingsections that are added as the drilling operations proceed, and thecenter or pilot hole cut by the bit is thus enlarged by the reamer whichfollows after the bit at the lower end of` the tool. The reaming tool isalso applicable for use without the end cutting bit, and, if required,the cutters of the rotary reamer mayv be utilized for cutting the metalpipe or well casing within which the reaming tool is located. Theprimary object of my invention is the provision of an expanding rotaryreamer by means of which many difficulties encountered in drillingoperations are avoided.A Provision is made for forcing the reamingcutters into expanded operative position by hydraulic pressure from theground surface, and the maintenance of the cutters in operative positionis indicated by the free and continuous flow of water from the casingabove the cutting tool, which flow or circulation continues only as longas the rotary reamers are in operative position. Means are provided forguiding and positively forcing the reaming cutters to operative positionand for' retaining them in working condition as will be described. Thereaming cutters are contracted and Withdrawn Within the tool bymechanical action of parts of the tool at the initial movement ofelevating or pulling the tool from the casing or hole. And lubrlcationof the vparts of the tool is provided for as will be hereinafter morefully set forth.

The invention consists essentially in certain novel combinations andarrangements of parts, involvin slidable members for radially andlateray moving the reamers or cutters to expanded or contractedposition, and in other features of construction as will be moreelaborately described and claimed.

In the accompanying drawings I have illustrated. one complete example,and several modlfication, of my invention wherein the parts are combinedand arranged according to the best modes l have thus far devised for thepractical application of the principles of my invention.

Figure 1 is a vertical longitudinal section of the tool with the reamersin expanded position for operation.

Figure 2 is a similar view with the reamers or cutters in contractedposition.

Figure 3 is a transverse sectional view at line 3-3 of Figure 1.

Figure 4 is a transverse sectional view through Figure 2 at line 1 4,showing the guide and retaining grooves for the reamers or cutters.

Figure 5 is a sectional view at line 5-5 of Figure 1 illustrating threereamers or cutters in expanded position for operation.

Figure 6 is a sectional view at line 6--6 of Flgure 1 at a threadedjoint and showing the squared driving shaft for rotating the reaming andcutting or drilling tool.

Figure 7 is an enlarged view, in perspective, of the cutter-holder withits integral driving shaft.

Figure 8 is a view in perspective at the lower end of the upper sleeveof the tool.

Figure 9 is a perspective'view complementary to Figure 8 illustratingthe upper end of the cutter-holder shell or sleeve, slotted toaccommodate the cutters.

Figures 10, 11, and 12 are perspective lid modified form of the devicefor actuating the expanding reamers.

Figure 17 islanother modified form of the expanding and lockingmechanism for the reamers, and Figure 18 is a transverse sectional viewof the locking device, at line 18-18 of both Figures 14; and 17.

For convenience of illustration the wellcasing and the center drillingbit are omitted from the drawings, but it will be understood thatthetool is suspended within the well casing by means of the threadsat'the nal opening 2 of the coupling member extends throughout thelength of the drilling tool, as will be described, and water underpressure is forced through the drill rod and tubular tool for expandingthe reamers. At its lower end .the coupling 1 is enlarged to form acylindrical head 3, and this head is packed to form a piston havingrelative movement within a cylindrical sleeve Il. A packing nut or gland5 enciroles the couplin member and is threaded, as by left han threadsinto the upper open end of the sleeve 4. `A cylinder head 6 is formed ofan annular, interior flange on the cylinder 4, and between the piston 3and head 6-an annular water chamber 7 is fashioned which communicateswith the bore of the coupling 1 and drill rod through port 7 in thecoupling. By means of water. pressure flowing through the bore 2 andport 7 into the water cylinder 7, as hereinafter described, the movableparts of the tool, by pressure applied to the head 6, are elevated fromposition' of Figure 2 to operative position of Figure 1, thus expandingthe reamer.

The piston portion 3 is provided with a packing ring 8 to revent leak ofwater from 'the cylinder 7, an it will be understood that the pistonremains stationary as the tool is elevated.

Below the sleeve 4 is located the barrel 9 which is secured to thesleeve by yleft hand ythreads 10, and this barrel, as best seen inFigure 9, is'provided with a plurality of diametrically arranged, openend slots 11, 12, and 13 at its upper end, and near its lower open endan interior flange 14 is fashioned. This flange has a squared openingtherethrough in line with the central axis of the tool to receive thesquared drive shaft 15 formed integral with the cutter holder 16. Thecutter holder is cylindrical and occupies the space within the barrel 9,and is secured to the lower end of the coupling 1 by means of thethreaded boss 3 thereonl which threads into the socket 16 of the holder.'llhus it will be seen that the barrel 9 which encases the holder isslidable relative to the holder, but rotates with the holder through thedrive shaft 15 and the complementary squared flange 14. The cutter`holder is fashioned with a series of undercut grooves 17 complementaryto the slots 11, 12 and 13 of the core barrel. These grooves extendlongitudinally of the holder and are vertically disposed in the toolhaving curved inner walls and undercut edges forming guide flanges 18 atthe sides of the grooves. rllhe grooves increase in depth from the topedge of the holder to the bottom of thegroove, .as best seen in Figure1, and are adapted to receive a set of reamers or cutters indicated as19 in Figures 10, 11, and 12., Each of the cutters has a top, roundedflange 20 and bot- .tom flange 20', and side flanges 21 the latterfittin under the flanges 18 of the grooves 1 which guide the cutters asthey move with relation to the holder and also retaintheni in position.lin inoperative position these cutters rest in the lower enlarged partsof the grooves 17 of the holder with their working faces projecting intothe slots as 11, 12 and 13 of the barrel, as seen in Figure 2. When thetool is actuated by water pressure to expand the cutters, the risingcore barrel lifts the cutters, and they ride upward in the grooves whichguide them to the tops of the grooves. As the cutters are elevated theyare alsok rojected lat erally and radially and by t e time they havereached the tops of the grooves the cutters are projected through theslots 11, 12 and 13, to operative position as in Figures 1 and 5. lnthis position the top flanges 20 are retained in complementary recesses22 in the head 3 of the coupling 1, and the bottom flanges 20 of thecutters are forced against the inner wall of the barrel 9 and clampedbetween the barrel and the holder,

as in Figure 1. The lower end of the squared driving shaft projects intoa sleeve 23 with a squared flange 23 similar to the barrel 9 andattached thereto by left-hand threads 24 at the upper end of the sleeveand the .lower end of the -barrel, and below. this sleeve'is attachedthe coupling head 25 by right-hand threads 26. The coupling head ishollow and provided fwith. an enlarged chamberv25 for Water.' 'llhevsquared driving shaft in combination with the squared flange insures apositive 'drive on turning movement adording' extensive wearing surfacesand great strength, though a key or spline might be used.

For limiting the movement of the sliding parts of the tool l utilize a`stop nut 27. threaded on the lower endroita the squared driving shaft,and in addition to performing its function as a stop, this nut also af-ILesaeea interior grooves 30 to render it resilient and is located justbelow the sleeve 28. rlhe lower end of the sleeve 28 is fashioned withan interior flange 31 forming a shoulder against which the head 32 ofthe valve casing contacts to limit downward movement of the valve casingwithin the sleeve.

lVithin the lower end of the tubular valve" member or valve casing isretained a. ball 33 adapted to close the seat 33 in the valve casingwhen forced to its seat by water pressure from above, which may flowdown throu h the drill rod and tubular drilling tool. n the exterior ofthe valve case or casing, near its lower end is secured a bushing 34, asby set screw 35, and the upper end of this hushing is fashioned with areduced extension 36 having a rounded top edge and adapted to enter andexpand the resilient clamp ring 30. When the tool is inoperative, thisresilient clamp ring 3() is clasped about the expander or extension 36,as in Figure 2. When Iwater pressure is applied to the tool to expand.the cutters 19 to operative position, the valve casing is first moveddownwardly from position of Figure 2 to that of Figure l. This movementslips the expander 36 out o the clamp ring 30, which ring is restingonthe inset ring 34 of the coupling head 25, and the expanded clamp ringimmediately contracts and clasps the valve'casing, as in Figure 1.

ln the lower'end of the valve casing are lateral diametrically extendingports 37 which also pass through the lixed bushing 34. When the tool isin inoperative position these ports are closed by the wall of thechamber 38 above the enlarged chamber 25 .of the head 25, but after thetool has expanded to operative position, the ports pass from the smallchamber to the larger one, and water is then tree to tlow trom the valvecasing through the ports 37 into the chamber 25 and thence into the holebeneath the tool. The bore oit the shell 23 is designated as a chamber39 in which the nut 27 on the end of the drive shalt is adapted tolreciprocate, in the expanding and contracting movements of the tool. @nthe lower end of the barrel 25 are 'threads ll0 to which the pilot bitVor lower. drill is attached, said drill not being shown in the drawings.

The cutters or reamers 19 may have a variety of cutting members asdiamond cut.- ters indicated at 2()a in Figures 10 and 11, or thecutting faces ot the cutters may vary as in Figure 12 to adapt thecutters or reaniers for various kinds of work.

ln preparing for drilling operations, be-

fore the tool is entered in the well hole, the cutters 19 are secured inretracted position within the core barrel 9, by pushing up the valvecasing so that the expander 36 will enter the split clamp ring 30, andby means of the frictional engagement of the expanded clamp ring on theexpander, and the fact that the clamp ring is seated on the insetring 34the tool holder is retained in the upper end of the barrel." 'lhecoupling head 25 is then threaded into the lower end ot the shell 23 andthe tubular coupling 1 is connected to the lower end of the tubulardrill rod not shown. rlhe tool. attached at the lower end of the drillrod is now lowered into the hole, or casing, and successive drill rodsections are added until the tool has reached the desired depth at whichpoint the reaming is to take place. lt necessary, water under pressuremaybe forced through the drill-rod and tool (the ball, valve 33 beingabsent) to wash away the dbris and providing for progress of the centerdrilling bit until thereamers or cutters have reached a point below thelower end of the lowest well casing or section. The water connection isthen removed from the top or surface end ot the drill rod and the ball33 is dropped through the tubular drill rod and tool to rest upon itsseat 33' in the valve casing or slide valve 29, thus closing the lowerepd of the tool against passage of water. l/Vater under pressure is thendischarged down through the tubular drill rod and into the tool, forcingthe ball valve tight against its seat. A pressure of between 150 and 500pounds will be suicient to force the slide valve from.

its position in Figure 2 to that ol Figure 1,

releasing the split clamp ring from its grasp on the expander 36 andforcing the head 32 of the slide valve to its seat 31 in the cylindricalsleeve 28, thus stopping the movement of the slide valve. rllhe splitring at this time has contracted and embraces the slide valve, and itsdiameter is sulliciently reduced to permit it to pass into the bore 38of the coupling head 25. Before the port 37 in the slide valve isuncovered', the pressure of water through the port 7 in the sleeve 4enters the cylinder 7 or chamber in this sleeve, and upward pressureagainst the head 6 will elevate the parts 9, 23 and 25 and parts carriedthereby, expanding the reamers or cutters as heretofore described. Asthe tool is lifted the coupling head l, tool holder or cutter holder 16and the squared shaft 15 remain stationary, and the port 37 is finallyuncovered. lWater is now released from the interior of the too-l andiows through port 37 into the enlarged chamber 25 and thence to thebottom of the hole. rlhe reaming cutters are now in operative positionand the tubular drill rod is revolved to impart rotary motion to the'cutter holder 16, the cutters or reamers 19 and the entire :ik J1 toolDCirculation of Weiter is provided for through the irill rofl, the tool7enel npvvsrcl from benentli the tool7 esteriorly tliereo, pest therotetingg reemers i9., wliere cutgs or clloris are carrieel upwztrtllytlirouggli tno well liole or cesing tlie surlece of the gronncl Tlierelease ofi @veter through the port or ports 37C andthe continued.circulntion of 'We/ter es eliove described intlicstes tliet tliereeiners in expended working position; entl it will else be eppoi-enttliet ell clovvnvvortl press-nreesenteil on tlie clrill the lower enelof tlie tool will lieve tendency to maintain the remmers in ope`r etivepositionn llie reemers ere tlius loeclrecl egoinst e soliol support eneltlre liolcler lo celtes tlie leterel tlirnst imposecl on tire reemersenel port or tlie die@ vvliile tlie grooves titl snol slots rvliiclieccommodlete reemers receive e pel-rt ot tlie rlrsg streins ol tliereemers.

Alfter e section of the liole lies 'been drilled endl resrned loy tlieprogressive9 tloivniverrl movement of tlie tool., the circnletion etvreter is stoppecl loy cutting cti tlie supply to tlie drill roel.,Alfter cutting oli' the water pressure, the drill rorl snol its tool erepulled from the Well liole in usuel mennen At tlie initial elevatingmovement or tlie clrill rofl enel tool, tlie suspentlecl parts el, il,23, 25 enel rlconnections together Witli. tlie ettecliecl pilot orcenter drill, ere byA their Weight, lieltl stetionery,'vvliile tlieolrill roel, tlrill liolrler lo, its sliett l5 ond connections arerelatively moved7 Slioulol the 'Weight ot' tliese "parte loe insuicientlor tlie purpose, contact ot tlie expended resmers l@ with tlie lowerenti of tlie ivell casingi vill liolcl tliese ports in stetioneryposition, While tlie rlrill roel coupling, rentner liolrle'r snelsqnorerl sliet nre elevetetl.. llne movement ofi tlie groovecl holderconse-s tlie remmers loe reti-noted or witlirlrevvn from tlieirprojecteel position in tlie slots ll, l2, ll, enel es tlie lrolclerrises tlie or cutters ere linslly sestecl in tlie 'bottoms ol ie groovesvvitli their 'working feces ivitlirlrewn within. tlie slots ll, l2, i3.The nist 2'? is to tlie tez i 59,3, ceri-ying; witli it tlie sliclevalve 39? the vulve, c p ring;1 550 snol sleeve 28 tne nut retniningtheir seine reletive positions es in it -gir-re l llie arcuate @groovesin Yie remmer liolcler @intl inoperune,

reen/1ere, `lie slide vslve in tliis instance, indicatori es l2 is ecomparatively long tube leaving; e slide movement in the tool esincliceterl liy tlotteol lines et tlie lower enel oi" the slitle valve.ll-lere o flanged liescl 27 is tlirceclerl on tlielower enel ot thesquared shaft in place ot tlie nut 27 of Figure l, enel tlie heeel lioson open flange 43 et the lower enel ol tlie squared slmitt The slidevalve eiitencls tlirougli this :Hnge enel also projects into tlie drillrool coupling; l5.

,llflien liyolrenlic pressure is lirst epplieol. preparatory toexpanding the reerning cut-- ters, the later-el port 4:6 in tliecoupling heed l5 remains closecl until liytlreulic pressure forces theslicle Valve down releasing the clamping ring and cmisirngj the annular,eX- terior shonller i7 to engage the Flange 43. By tliis time the upperenol ot the slide valve lies uncovered later-el port i6 to sclmit Wateri pressure loeneetli the heed 4l of the sleeve 4:8. But tlie slirlsloleparts ol tlie tool are not elevated until the split clamp ring t9 liesrelessecl tliem. This ring is similar in construction to the ring 30 butis locatecl in e different' relative position. lt is retained ivitliinen ennuler groove 50 in the coupling lionel 'l5 and lies e number olclistending,1 pins 5l located in rsolislly extendingia complementarysockets in the lieecl. 'llie elasticity et tliis split ring liolils thepins Witli their inner pointed entls in contact with the exteriorsurface oi tl'ie slide velve l2, neer its Upper enel, snol in thispositionJ tlie split ring is lielcl clistended or expended. l/lliile inretracted or inoperative position tlie iesmers ere locked one relativemovement ot tlie sliding; parte of the tool snol tlie tool holder isprevented; loeceuse tlie split ring is sentori on en annuler 53 ot tliesliell 5l. llllien tlie slicle vslve is pusliefl' clown trom position otFigure le its upper enel is tv'itlrclrevrn from contact with pins 5lsplit ring is contrecterl clue to its elesticitys ln its contrecteclposition tlie split ring is enclosed Witliin tlie annuler groove enel :lfrom sees-t on tlie 539 tions permitting liytlrenlic pressure to enoentl te roaming cutters to operetiveposie enpsnsion movement oit tinereemtlie contraction movement tio-e are etteineti by the action es lsnol Q.

c le e zlnrt nionlice n oit c ing)ya ineens Jfor lioloing rs ininoperative position illusn o connection l s lower endiol lll@ withgeese to holcl, teinp(nfzniljyv the cong pling head 60 its requieflclistenee lnelovv the 'need 64e o1 the tlneeecl bushing 65. This bushingis shouldered et 66 to receive the isnge 67 of the valve heed, 56 enelthe bushing lies external threads toi.' tlie sleeve 68 within the shell6l. )in Figure 16 the slide valve, which pieviously lied been held inelevated position, by grease packed as tlirougli the grease port 69 inthe Well of the diill holden oi: heeel '30, lies been olepiessed byWater piessme in the slie valve And tlie heeel 56 oi: the valve liesbeen moved from contest with the lowes enel of the squared shaft l5.This movement llas pnsliee the peeking 1fing 59 pest the moutli oioutlet opening et the grease port 69 enel in tlie position showincontinued liydmulie pi'essnie on the bell 705 causes e beek or upweiclpiessin'e in the tool for lifting the heed 6 of Figure l. Pressure onthe heeel 6 elevetes the slidingn petits of the tool to expanii tlieteeming entteis and the gi'esse in elisniliet- 63 is foieed out es theniemnei 5G is elevated in Fig 16.,

This foin of tlie invention is especially' adapted for oliillingeompsiatively shallow wells5 and the grease paeliecl in, its chenille?7with the valve elevsteci sufeiently to close tlie outlet port 695ifeteins tlie euttei's oi ieeniers in looked inoperative position untilthe lively-eolie pessuie is epplie as here toitoie Clesefiloed;

ln liguies 17 enel l e further moiiiestion ot tlie tool is illustratedcombining the comparatively long slide valve and resilient ring of niceles Witli the expanden enel, iresilient ting el Figures 'l snel 2. Theaction of the tool nnei liyelmulie pressure, in this instenee is thesaine es that pteviously tieseiioeels lont the duplex resilient oielastic Clamping `sings Whieli look the parte in in ope-native positionliolcl the parts more seeuely and support e loew/ietF loeolg l From'tlie shove eieseription taken in conn on with my citeer/ings it vwill beeppen- Llie tool es suspended from tlie shaft, is temporarily loosen-7.v-Jitli tee reenies oi eutteis in inopeetive nosition in otflei' thatthe tool may be into tite Well easing oi hole. 'lllie nets se positivelyenpendeel oi* projeeo by liydieulie presgea .1 4.1 snfe siglo, Steeleposition 1* 1 ,m ttin: i ioo eno tool efe le volv setiseteo; to inopeoconvenience met it may e te ities ie process o;

nii outsole ln eerliei eonstiuetion itwes impossible to keep geit ori'oelt particles tem entesm ing the bestel, 9 anni Wearing the gtoovesenelv feces? sn even elioliing the barrel so that the cutteis could notfunction.. lt Wes 7 also impossible to piroteet tlie oeiloons oi"-elieinonds fiom being broken? tlispleeecl enel lost ln the presenteonstiuotion tlie onto ters lit exactly in the slots in tlie bestelkeep-1 ing out ell foreign metter enel tlitongli the functioning o themenate gnieie tlie euttets are ietraeteel enel tipped so that tliepteeious stones are guarded ami pioteete Having tlins fully oleseiiloetlmy inveitn tion, what l eleini es new and @lesite to sed eure leyLetters Patent is* l. 'llie combination with relatively stem tionei'yhollow euttei liolen en hollow drill rofl, oie movable tool includingteelieily enpensiole teaming mettete enel ineens tot admitting hydraulicpiessnte to the tool for expanding seid vteeming entteis 2: Theeonibinetion with e elsitively' stetioneiy hollow enttei holden entielisil oi a suspended tool enel ineens tot one miily holding saisi toolin suspensiwi9 ineens tot admitting loyelreulie @fessure the toolWlieieoy the lette? is ,mov-eil to @ptetn etive position,

3, The combination in e i` i:i".ng too @lading e rotary coupling 'heeel.hollow cutter liolelei enel' enpsnsilole entteis een iieel thereby, onts Totem] too-l soepen@ n' seid coupling heed, ineens fot f flieuliepressure to the toole en ineens Wlieieby tlie tool is moved relativelyto liolciei1 oi" expanding seid veuttetss t. The combination with ateletively tioneiry hollow till-tool coupling enel ontn tei holder'forming e eliivi monili-ei: een-J neeted thereto and e heed. oi the een'l of e tubular slieizilole tool? est sensible euttets ee'fiied by seidholden5 e lieeo on. tlie tool means for teinpoietily ieteining tlie toolin sus'peniieol position? eno eens Een admitting hydraulic piessnie lLveen seid liesds tot moving the tool ent-tees to operative position 5.lie combination in e tots with e tubular eouplinff heed enttei" le entieutteis and e polygonal f l im..

iiietion soup linr1 co-acting means on the holder and tool member forlaterally projecting said cutters lovv grooved holder and cutterstherein, of

a slotted movable member forming part or said tool and engaging saidcutters, and means for admitting hydraulic pressure to said tool formoving the latter and expanding said cutters to operative position.

"8, The combination in a ieaming tool including a rotary tubularcoupling head, a hollow cutter holder and cutters carried thereby and anintegral drive shalt, ol a hollow sectional tool member suspended fromsaid head and operatively connected with said shalt, means lor temorarily sus'- pending said tool and locking t e cutters in inoperativeposition, and means actuated by hydraulic pressure lor releasing saidloclring means and moving said tool member to expand said cutters.`

9. rllhe combination in a rotary roaming tool with a tubular couplinghead, a cutter holder having a polygonal drive shalt, and

expansible cutters carried by said holder, oty

an upper sleeve on the coupling head torminn1 a head and cylinderadapted to receive Water pressure from the coupling head, a slottedbarrel connected with said sleeve and encasing the holder, a shellconnected with said barrel and encasing said shalt, a lower couplinenhead connected with said shell, means ror supporting said sleeve,barrel, shell and lower coupling from said tirst mentioned couplinglhead and means Whereby, when said members are suspended by Waterpressure in said cylinder, the cutters are expanded.

lll., The `combination in a rotary roaming `tool `with a longitudinallygrooved cutter holder a cutter in said groove, of a relatively movableslotted tool member encasing and adapted 'to engage said cutid move it''to radially extended posination in a rotary th cutter holder havinglonfi tending exterior groove increas' h tovv'wf'd one end, et cuttersaid cutter through ry movable slotted to cutter, l

said member to pr l position.

ion in rotary reamer cutter der l ying en exterior untlanges, `l

bil@

f having lateral i r. fr aiolguide Menges, a

i EO'Ol.

Mannes for moving said member to project the cutter to operativeposition.

13.. 'llhe combination in a rotary expansible reamer with relativelystationary tool supporting memberso tubular constructionand relativelymovable tubular members, and means for expanding the tool to operativeposition by hydraulic pressure, ol means lor supporting the movablemembers vvith the tool in inoperative position', said means beingreleasable under hydraulic pressure.

lll. The combination in rotary enpansin ble reamer having relativelystationary tubular supporting and driving members and movable tubularmembers (3o-acting therewith to expand the tool to operative positionunder hydraulic pressure, of a slide valve operatively connected withthe stationary -and movable members, and means 85 tro-acting with saidslide valve or temporarily locking the expansible reamer in contractedposition.

l5. r)The combination in a rotary roaming tool with tubular supportingand driving members, of relatively movable tubular members adapted toco-act therewith for expanding the tool to operative position underhydraulic pressure, a tubular slide valve connecting the stationary andmovable members and adapted to resist hydraulic pressure, means fortemporarily holding y saidvalve to maintain the tool in inoperativeposition, and said holding means being releasable under hydraulicpressure.

16. lhe combination in a roaming tool With a stationary supportingmember and movable driving member as described., of a tubular slidevalve operatively connected with said members, ring adapted to temporeily i in locked position 'for the pu li. The combination vith stationarysupper-tir driving members as descr slide valve connecting detachableloelring mem er cf' valve adapted hol? inoperative positiono i8. 'lhecombination with I stationary snj A.ng asicesci slide valve sup membereng a resilientl clamp by movement oif said t able member i0, The oonnatio tool with ho Leeeea able tool member for radially projecting saidcutters to operative position.

20. The combination in a rotary reaming tool with a longitudinallyarcuate grooved 5 cutter holder and a flanged cutter operative in saidgroove', said cutter havin top and bottom flanges for engaging tiecutter holder and a movable slotted tool member respectively, of arelatively movable slotted tool member encasing said holder and 10adapted to engage said cutter ard move it to radially extended position.

In testimony whereof l aflix my signature.

FREDERICK STONE.

